關聯式資料庫自1970年代開始主導了資料庫儲存管理模式達數十年，然而近年來隨著雲端運算(Cloud Computing)急速成長，產生了海量資料(Big Data)的儲存管理的衝擊，傳統關聯式資料庫已經無法有效的儲存、查詢或分析海量資料，為了解決此問題，進而產生了NoSQL(Not Only SQL)資料庫之管理模式。
目前雖有多種NoSQL資料庫能夠提供給使用者查詢與異動資料庫的介面，但都不支援標準SQL語法類似的功能，Google App Engine使用的資料庫Datastore提供GQL(Google Query Language)語法，雖類似SQL，但不全然相同。關聯式資料庫與NoSQL資料庫是為了各自不同的目的而存在的，當企業有海量資料的需求時，勢必要將關聯式資料庫移轉到NoSQL海量資料庫，同時保持資料的關聯性。使用新資料庫若還需要學習新的語法或是無法達到資料關聯(JOIN)的查詢，都是非常不便利的，且標準SQL語法已經被廣泛學習且熟知。
本研究提出一個介面，可以將標準SQL語法轉譯為GQL語法，並可針對轉入海量資料庫之資料做新增(INSERT)、修改(UPDATE)、刪除(DELETE)及查詢(SELECT)。且在Google App Engine上實作該介面，達到了資料關聯(JOIN)特性、聚合函數(Aggregation)、子查詢(Subquery)等功能。因此使用本研究的實作介面時，使用者可以不需要另外學習NoSQL資料庫的語法，直接使用標準SQL語法，就可使用NoSQL資料庫，形同操作關聯式資料庫一般。

In recent years with the rapid growth of network business applications and the cloud computing, issues of Big Data emerge and impact the data storage management of database. It is recognized traditional relational database is unsuitable to store, query, or analyze such enormous data effectively. In order to solve this problem, NoSQL (Not Only SQL) database appear. Big names in web services, such as Amazon, Cassandra, and Google, provide direct query web interface and transaction APIs to the developers for using their NoSQL database. As the name Not Only SQL suggests, these databases do not fully support the standard SQL language. For example, the GQL (Google Query Language) is a SQL-like language for retrieving entities or keys from the App Engine scalable datastore maintained by the Google. Although the GQL has syntax similar to that of the SQL, they are not identical. Relational databases and NoSQL databases exists for different purposes. Developers have been using the SQL language for various database management systems for a long time. When they try to migrate from relational database to some NoSQL database, they have to learn the new syntax of NoSQL languages and, to be even worse, most NoSQL languages cannot perform join operations. This study develops an interface to translate standard SQL syntax into GQL syntax and manipulate the datastore by Insert, Update, Delete and Select operations that uses Google App Engine under the hood. The interface is able to support SQL Joins, Aggregate functions, and Subqueries. Therefore, when using this interface, developers can use standard SQL syntax on NoSQL databases, just like they are using SQL on relational databases.

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